The present invention relates to receiving terminals, receivers and receiving methods for CDMA (Code Division Multiple access) system and, more particularly, receiving terminals for CDMA system capable of reducing power consumption.
FIG. 8 is a block diagram showing a prior art receiving terminal for CDMA system. The receiving terminal for CDMA system comprises an antenna 110, a radio circuit 120, a finger circuit 130 including a plurality of (i.e., six in the illustrated example) finger circuit elements, a rake circuit 140 including a synthesizer and a level measuring circuit, a timing circuit 150, a Viterbi circuit 160, a codec circuit 170, a loudspeaker 180 and a crystal oscillator 190.
The finger circuit 130 includes six finger circuit elements (1) to (6), which each obtain a correlation between a received signal fed out from the radio circuit 120 and a known signal and feed out the resultant correlated value of the received signal to the rake circuit 140. The timing circuit 150 determines the timings for obtaining the correlated values in the finger circuit 130. The individual finger circuit elements (1) to (6) obtain the correlated values under control of a pulse signal fed out for every 10 msec. from the timing circuit 150 as triggers. The rake circuit 140 executes synthesis of the correlated values of the received signal and level measurement. The Viterbi circuit 160 executes error correction of the synthesized received signal from the rake circuit 140. The codec circuit 170 converts the corrected received signal from the rake circuit 140 to a voice signal, which is fed out to the loudspeaker 180 for outputting voice. The crystal oscillator 190 generates clocks for controlling the operation of various components.
In the prior art described above, however, the finger circuit 130 and timing circuit 150 operate independently of the level of the received signal. This leads to a problem that the power consumption is increased or is too high.